National Cancer Institute (source definition)
Tissue Culture Infectious Dose 50%
A potency unit defined as a minimal dose of infectious material at which preparation causes cytopathic effects (changes in the morphology and metabolism of tissue culture cells, indicating cell death, due to suspected infection) in the 50% of the tissue culture-containing flasks inoculated with that dilution of infectious material in the product potency assay or pathogen activity assay.
Review and references
Automated source check (NCI definition)
2026-10-20
2026-10-20
professional use
What it is
A potency unit defined as a minimal dose of infectious material at which preparation causes cytopathic effects (changes in the morphology and metabolism of tissue culture cells, indicating cell death, due to suspected infection) in the 50% of the tissue culture-containing flasks inoculated with that dilution of infectious material in the product potency assay or pathogen activity assay.
Source: National Cancer Institute, NCI Thesaurus 26.09d, C67450. NCI definition, reproduced without modification under CC BY 4.0.
Source identity and definition checked automatically on 2026-10-20. No individual clinical interpretation or human reviewer is asserted.
Compliance note
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.